This invention relates to an infant-restraining protective seat of the type placed upon and secured to a seat in a vehicle such as an automobile or airplane and adapted to restrain and protect a seated infant by a seat belt device for infants. More particularly, the invention relates to a shoulder-belt adjusting device for adjusting the shoulder belts of the seat belt device for infants.
In a vehicle such as an automobile or airplane, restraining protective seats for infants have been used in order to maintain the seated posture of an infant during travel and protect the infant from shock at the time of acceleration and deceleration. An infant restraining and protective seat of this kind has a reclinable seat main body reclinably attached to a base member and adapted to seat an infant, and an infant seat belt device for restraining the seated infant. The infant seat belt device has an infant seat belt, a chest-contact pad attached to the end of the infant seat belt, a tongue provided on the end of the chest-contact pad, and a buckle, provided on the seat main body, capable of holding the tongue in such a manner that the tongue can be freely engaged with and disengaged from the buckle. In a state in which the tongue is engaged with and locked by the buckle, the infant is restrained by the infant seat belt and chest-contact pad.
Since the height of the shoulders of a seated infant differs depending upon the build of the infant, the conventional infant-restraining protective seat of this type is equipped with a shoulder-belt adjusting device which, in dependence upon the build of the seated infant, adjusts the up-and-down position of the infant shoulder belts engaging the shoulders of the infant.
The conventional shoulder-belt adjusting device in common use includes a suitable number of adjusting holes, which are provided in the seat back in the longitudinal direction, through which the shoulder belts are passed. The positions of the shoulder belts are adjusted up or down by passing the shoulder belts through those adjusting holes corresponding to the build of the infant.
However, in the up-and-down adjustment of the shoulder belts by the longitudinally provided suitable number of adjusting holes, the adjustment is performed in individual steps, and therefore the shoulder belts cannot be adjusted accurately in conformity with the build of the infant.
Accordingly, a shoulder-belt adjusting device in which the positions of the shoulder belts up and down can be adjusted steplessly has been developed. The shoulder-belt adjusting device includes a belt guide for guiding the shoulder belts up and down, a screw shaft rotatably disposed on the back side of the seat back along the longitudinal direction for moving the belt guide up and down, and an operating knob disposed on the upper end of the seat back on its back side for applying a rotational torque to the screw shaft. By turning the operating knob to move the belt guide up or down, the positions of the shoulder belts can be steplessly adjusted up or down.
However, in this shoulder-belt adjusting device, the amount of projection of the infant-restraining protective seat 1 to the rear is large since the operating knob is disposed on the upper end of the seat back on the back side thereof. In particular, when the protective seat is used, the seat back assumes a reclining attitude tilted to the rear and therefore the amount of rearward projection of the upper end of the seat back is enlarged.
Thus, when the infant-restraining protective seat having this large amount of rearward projection is secured to the vehicle seat, the protective seat is situated at a considerably forward portion of the vehicle seat. As a consequence, the seated infant is too close to the parts of the vehicle in front of the vehicle seat. Moreover, owing to the fact that the protective seat is disposed on the forward part of the vehicle seat, there are cases in which the protective seat cannot be secured to the vehicle seat stably and reliably.